Waste Treatment - Reducing Global Waste

Reducing global Waste

Waste Treatment

Waste Treatment

REDUCING GLOBAL WASTE

Anne Maczulak, Ph.D.

GREEN TECHNOLOGY

WASTE TREATMENT: Reducing Global Waste

Copyright 2010 by Anne Maczulak, Ph.D. All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher. For information contact: Facts On File, Inc.An imprint of Infobase Publishing132 West 31st StreetNew York NY 10001

Library of Congress Cataloging-in-Publication Data

Maczulak, Anne E. (Anne Elizabeth), 1954 Waste treatment : reducing global waste / Anne E. Maczulak. p. cm. (Green technology ; v. 2) Includes bibliographical references and index. ISBN-13: 978-0-8160-7204-0 (hardcover) ISBN-10: 0-8160-7204-3 (hardcover) ISBN: 978-1-4381-2611-1 (e-book) 1. Refuse and refuse disposalJuvenile literature. 2. Waste minimizationJuvenile literature. 3. Recycling (Waste, etc.)Juvenile literature. I. Title. TD792.M35 2010 628.4dc22 2008045054

Facts On File books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755.

You can find Facts On File on the World Wide Web at http://www.factsonfile.com

Text design by James Scotto-LavinoIllustrations by Bobbi McCutcheonPhoto research by Elizabeth H. Oakes

Printed in the United States of America

Bang Hermitage 10 9 8 7 6 5 4 3 2 1

This book is printed on acid-free paper.

Preface ixAcknowledgments xiIntroduction xiii

1 AssessingGlobalWasteManagement 1Th e Growing Problem of Garbage and Waste 2Hazardous and Nonhazardous Waste 3Waste Streams 9Ecosystem Health 11Waste Management 14Waste Transport 16Landfi lling 22Case Study: Th e Birth of a Th rowaway Society 28Separation and Treatment Technology 28Th e Salvage Industry 30Case Study: DenmarkA Model in Waste Management 31Conclusion 34

2 ElectronicProductsandMetals 36Components of E-Waste 39Household Batteries 42Electronics Pollution 43Heavy Metals from E-Waste 44White Goods 45Separation and Reuse 47Case Study: Community Answers to Surplus Computers 50

Contents

New Technologies for Reducing E-Waste 51Clean Computers 53Conclusion 55

3 Incineration 57Methods in Municipal Waste Incineration 60Incineration and Energy Production 63Case Study: The Development of the Clean Air Act 64Incinerated Materials and Air Quality 70Hospital Waste 72Clean Incineration 74Risk Assessment and Global Needs 75Conclusion 77

4 Vitrification 79History of Vitrification 80High-Level Radioactive Waste 84The Properties of Glass 85Handling Immobilized Waste 87Case Study: The Hanford Nuclear Waste Site 88Innovations for Vitrifying Radioactive Waste 94Enriched Uranium and Plutonium 95Conclusion 100

5 SolidificationandStabilization 101Controlling Solid and Liquid Waste Streams 102The Sediment Cycle 104Rachel Carson 106Solidification 106Chemical and Biological Stabilization 109Case Study: The Sandoz Chemical Spill in Switzerland 113Underground Disposal 115Yucca Mountain Disposal Site 118

New Technologies in Waste Stabilization 121Conclusion 123

6 ReductionandCompaction 125Nonhazardous Solid Waste 127Volume Reduction 128Composting 130Compaction Systems 133Organic Fertilizers 135Paper Compaction 137Products from Compacted Waste 139Conclusion 142

7 WastewaterTreatment 143The History of Sanitation 143Constituents of Wastewater 145Nitrogen and Phosphorus 148Wastewater Treatment and Disposal Methods 149Septic Systems 152Physical and Chemical Treatments 152Biological Treatments 156Natural Treatment Systems 157Case Study: Wetland Waste Treatment in California 158Reclamation and Reuse 161Case Study: San Diegos Recycled Water 163Conclusion 165

8 FutureNeeds 167

Glossary 169FurtherResources 176Index 189

ii

Preface

T he fi rst Earth Day took place on April 22, 1970, and occurred mainly because a handful of farsighted people understood the damage being infl icted daily on the environment. Th ey understood also that natural resources do not last forever. An increasing rate of environmental disasters, hazardous waste spills, and wholesale destruction of forests, clean water, and other resources convinced Earth Days founders that saving the envi-ronment would require a determined eff ort from scientists and nonscien-tists alike. Environmental science thus traces its birth to the early 1970s.

Environmental scientists at fi rst had a hard time convincing the world of oncoming calamity. Small daily changes to the environment are more diffi cult to see than single explosive events. As it happened the environ-ment was being assaulted by both small damages and huge disasters. Th e public and its leaders could not ignore festering waste dumps, illnesses caused by pollution, or stretches of land no longer able to sustain life. Environmental laws began to take shape in the decade following the fi rst Earth Day. With them, environmental science grew from a curiosity to a specialty taught in hundreds of universities.

Th e condition of the environment is constantly changing, but almost all scientists now agree it is not changing for the good. Th ey agree on one other thing as well: Human activities are the major reason for the incred-ible harm dealt to the environment in the last 100 years. Some of these changes cannot be reversed. Environmental scientists therefore split their energies in addressing three aspects of ecology: cleaning up the damage already done to the Earth, changing current uses of natural resources, and developing new technologies to conserve Earths remaining natural resources. Th ese objectives are part of the green movement. When new technologies are invented to fulfi ll the objectives, they can collectively be called green technology. Green Technology is a multivolume set that explores new methods for repairing and restoring the environment. Th e

Waste Treatment

set covers a broad range of subjects as indicated by the following titles of each book:

Cleaning Up the EnvironmentWaste TreatmentBiodiversityConservationPollutionSustainabilityEnvironmental EngineeringRenewable Energy

Each volume gives brief historical background on the subject and current technologies. New technologies in environmental science are the focus of the remainder of each volume. Some green technologies are more theoretical than real, and their use is far in the future. Other green tech-nologies have moved into the mainstream of life in this country. Recy-cling, alternative energies, energy-efficient buildings, and biotechnology are examples of green technologies in use today.

This set of books does not ignore the importance of local efforts by ordinary citizens to preserve the environment. It explains also the role played by large international organizations in getting different countries and cultures to find common ground for using natural resources. Green Technology is therefore part science and part social study. As a biologist, I am encouraged by the innovative science that is directed toward rescuing the environment from further damage. One goal of this set is to explain the scientific opportunities available for students in environmental stud-ies. I am also encouraged by the dedication of environmental organiza-tions, but I recognize the challenges that must still be overcome to halt further destruction of the environment. Readers of this book will also identify many challenges of technology and within society for preserving Earth. Perhaps this book will give students inspiration to put their unique talents toward cleaning up the environment.

ii

Acknowledgments

I would like to thank a group of people who made this book possible. Appreciation goes to Bobbi McCutcheon who helped turn my unre-fi ned and theoretical ideas into clear, straightforward illustrations. Th anks also go to Elizabeth Oakes, Ph.D., for providing photographs that recount the past and the present of environmental technology. My thanks also go to Marilyn Makepeace, who provided support and balance to my writing life, and Jodie Rhodes, who helped me overcome more than one challenge. I appreciate the guidance I received from Bruce J. Murphy of IntelliWaste, Inc., on the fi ne points of waste management and from S. K. Sundaram, Ph.D., of the Pacifi c Northwest National Laboratory on the background of vitrifi cation. Finally, I thank Frank Darmstadt, executive editor, for his patience and encouragement throughout my early and late struggles to produce a worthy product. General thanks go to Facts On File for giving me this opportunity.

iiiiii

E very living thing, from microscopic bacterial cells to giant redwood trees, takes in nutrients and excretes wastes. Nutrients fuel the inner workings of all animals, plants, and single-celled organisms. Aft er using nutrients, each cell of every living thing produces waste. Biological wastes from one organism are very oft en used as nutrients by another being. An easy example to visualize is the oxygen given off as an end product of photosynthesis in plants, which is then used by animal cells. Th is form of recycling serves a useful purpose, because if biological end products accu-mulate in the environment, they eventually inhibit other forms of life.

Humans have developed most of their working machinery based on the simple biological model of nutrients in and wastes out. Humans take in fuel and expel wastes; machines take in fuel and expel wastes. Wastes from equipment, vehicles, appliances, and other nonbiological things would build up and halt human activities if they were left unattended, just the same way excess cellular end products begin to harm cells. Th e main end products from machinery are gas emissions, used oil, ash, and heat. Th e subject of this book is waste treatment technology. Waste treatment is the removal of wastes from the environment by burning, decomposing, or chemically transforming them so that Earths activities can continue. It is one of the most critical phases of waste management.

Th is volume in the Green Technology set explores how the waste treat-ment industry plays a role in removing, treating, and disposing of human, household, and industrial wastes. Waste Treatment begins with a look at the global waste problem. It defi nes the diff erent classifi cations of materi-als that are treated today in waste management. One of the most impor-tant concepts in waste management is the waste stream. Waste streams are all the sources of various wastes as they move through the environment toward a fi nal disposal. Th e control of waste streams is the central theme throughout this book.

Introduction

iv Waste Treatment

This book also presents the ways in which hazardous and nonhazard-ous wastes are defined. These classifications are more than just a curiosity. Waste managers can make better decisions on treatment methods when wastes are grouped by their physical form, chemical content, degree of haz-ard to the environment, or source. These groupings also allow environmen-tal scientists to learn about the trends in our societys waste and in society itself. Waste types can change quite dramatically in a period of less than 100 years. For example, this book shows how wastes from electronic prod-ucts are a big problem in the world today but certainly were not a concern in the early 1900s. But in 1910, for instance, horse manure from the use of thousands of horse-drawn vehicles was probably a huge waste problem!

Chapter 1 gives an overview of the worlds waste problem. Special aspects of waste management are explained. Some of the key aspects are

Modern waste management programs aim to minimize the total amount of nonreusable waste and maximize the amount of reusable waste. The ultimate goal in sustainability is waste prevention.

Introduction v

the following: (1) the reasons for waste categories; (2) selection of the best waste treatment method; (3) the role of landfills; (4) waste transport requirements; and (5) the relationship between waste buildup and ecosys-tem health.

Chapter 2 discusses the unique challenge of one of the worlds most pressing waste problems: discarded electronic products. These items have accumulated quickly in the past two decades. Stockpiles of used or obso-lete electronic waste, e-waste, are reaching alarming levels in developed and developing countries. The chapter discusses why e-waste is a particu-lar hazard in developing regions of the world. The treatment of e-waste is unlike that of any other waste. The chapter describes the steps for salvag-ing the components of e-waste and the special hazards contained in this waste category.

Chapters 3 and 4 present the advantages and disadvantages of two ther-mal methods in waste treatment: incineration and vitrification. Incinera-tion has been a dependable waste treatment method for a century. Chapter 3 discusses familiar drawbacks and perceptions of incinerator emissions. It also describes new technologies for changing incineration from an unde-sirable treatment method to a surprisingly groundbreaking technology and offers a case study on the development of the Clean Air Act.

Chapter 4 focuses on the worlds most innovative thermal method for treating highly hazardous radioactive and nonradioactive wastes: vitri-fication. It describes this technology and the reason why it may become the United Statess last best hope for disposing of its stockpile of nuclear wastes. It also illustrates the hurdles towns face when they desire new waste treatment technologies. Finally, the chapter explains the basics of radioactive materials.

Chapter 5 looks at ways in which wastes in the environment can be made stationary so they do not harm uncontaminated places. Solidifica-tion and stabilization name two related technologies that are now using new chemical formulas and simple biological techniques to hold pollut-ants in the soil in a safe form. The chapter pays special attention to the current status of Yucca Mountains proposed hazardous waste site. The problems related to this government operation are described in this chap-ter, but Yucca Mountain is mentioned throughout the book because of its importance to a number of hazardous waste programs in this country.

Chapter 6 reviews two technologies used on wastes that are not treated by traditional combustion methods. It describes reduction methods and

vi Waste Treatment

compaction methods. Special attention is given to the ways in which com-pacted materials are now designed for sustainable uses.

Waste Treatment concludes with a chapter describing wastewater treat-ment. The chapter explains how wastewater treatment is actually a form of bioremediation and why wastewaters are distinct from almost every other kind of hazardous waste. The current chemical, physical, and biological steps in wastewater treatment are covered as well in new technologies for removing biological and nonbiological waste matter. This chapter also delves into approaches for using wetlands to help purify surface waters.

Waste Treatment follows a theme begun in Cleaning Up the Envi-ronment, the first book in the Green Technology set. Todays hazardous waste management is usually a mixture of cleanup and treatment meth-ods at the same hazardous waste site. Hazardous waste stockpiles are also increasingly being managed with technologies that combine cleanup and treatment within the same process. In fact, few projects in contamination cleanup do not use some combination of methods. Cleaning Up the Envi-ronment and Waste Treatment describe these cleanup/treatment technol-ogies and why they are an advantage in hazardous waste management.

Perhaps the most interesting message offered by these chapters is the relationship between society and its wastes. The types, amounts, and stor-

Waste management has increasingly turned to methods that combine pollution cleanup with treatment. Other technologies dedicated to either cleanup or treatment may then supplement cleanup/treatment combinations. This increases the overall efficiency of managing hazardous wastes.

Introduction vii

age of wastes in the world today tell a story about the way people live. They give clues about societys level of technology. Waste buildup or its reduction over time also tells scientists how well populations are doing in restoring their planet.

1

A typical person living in an industrialized country discards about 4.5 pounds (2 kg) of solid waste each day, but household garbage makes up only a portion of the solid wastes generated every day. Offi ces, construction sites, restaurants, farms, and manufacturing plants produce most of the solid wastes generated every day. In addition to solid wastes, thousands of gallons of wastewaters from towns and cities and hazardous liquids from businesses contribute to total global waste. Before any com-munity, city, or country can safely remove and dispose of these materials, people must understand the nature of waste, meaning its solid or liquid characteristics and its potential hazards. Waste management comprises all activities that deal with every aspect of solid and liquid waste: collection, transport, recycling, and disposal.

At present there is hardly a place on Earth that has not been exposed to some sort of waste. Some of these materials cause immediate health hazards to humans and animals. Other wastes persist for years in the environment until they reach levels damaging to healthy ecosystems. An ecosystem is the complex of plants and animals that interact with each other and their surrounding environment. It is critical to keep ecosys-tems working properly because the health of Earths biomes depends on the combined activities of individual ecosystems. Pollution causes a situa-tion in ecosystems called ecosystem imbalance in which food and physical conditions are no longer adequate for the ecosystems normal inhabitants. Damaged ecosystems soon disrupt the normal workings of entire com-munities, which are all the populations of living things in a defi ned area.

1A G

W M

Waste Treatment

In time, Earths biomes feel the effects of waste buildup. Waste managers today know that even small amounts of waste may in time lead to global environmental problems. This chapter describes the types of waste that upset ecosystems and the ways in which small amounts of waste can grow into large environmental hazards. The chapter introduces the concept of waste streams, describes the responsibilities in waste management, and discusses two important aspects of waste management: transport and landfill disposal. Finally, this chapter describes the increasingly important salvage industry.

The GrowinG Problem of GarbaGe and wasTe

People know waste when they see it. A Dumpster piled high with garbage bags, a pickup filled with old computers, containers of used aluminum cans and newspapersthese are obvious signs of waste. Additional mate-rials enter the environment each day less noticed. These unseen materials are of greatest concern because they enter ecosystems silently. They may be chemicals dissolved in river water, gases in car emissions, or tiny bits of oil in dunes on a beach. In order to understand the total amount of wastes entering the environment, all of the visible and invisible substances must be considered.

The waste materials made in any region of the world can be thought of as related to the populations wealth, because wealth often affects a regions technologies. Industrialized countries annually generate more than 450 million tons (408 million metric tons) of solid waste. In the United States alone, solid waste generation has increased 235 percent in the last 40 years to more than 12 billion tons (11 billion metric tons) annually. Despite this growth, disposal methods remain quite primitive, especially when com-pared with advances in other technologiescomputers, space explora-tion, and biotechnologyduring the same period. Burning and burying still play major roles in waste disposal as they did in the earliest human societies.

The types of waste have changed throughout human history as tech-nology has changed, but the puzzle of how to dispose of them has lasted. Apparently early civilization had as difficult a time in waste management as people do today. For instance, archaeologists examining ancient sites dating to 6500 b.c.e. in what is now Colorado have determined that settle-

Assessing Global Waste Management

ment dwellers may have discarded as much as five pounds (2.3 kg) of waste a day.

The history of waste began with the history of humans, but waste grew into a serious problem when societies began building their commerce. For centuries, people living in rural areas or towns either burned much of their household waste or dumped it into swamps and rivers. Waterways became so clogged in England that Parliament in 1388 banned the use of rivers for waste disposal simply so boats could make their way upstream. The land took its share of wastes too. In 1400, the garbage hauled out of Paris formed mountains so great outside the city that travelers were hard-pressed to find routes in and out.

The United States experienced a similar dilemma when its population expanded and its economy began to grow. U.S. businesses followed the familiar prescriptions for waste disposal: burning, burying, or dumping into waters. In time, U.S. waterways had become almost as clogged as the English rivers in the Middle Ages, and by 1899 Congress passed the Riv-ers and Harbors Act to ban the discharge of solid and liquid wastes into waterways used by boats. Despite these steps, people remained surpris-ingly slow to grasp the dangers of toxic and infectious materials filling the environment. Not until 1978 when the Love Canal area near Niagara Falls, New York, became so engorged with dumped chemicals that they seeped into schools and homes and made residents ill, did the government awaken to the need for hazardous waste controls. Today, individual and industrial wastes are managed more carefully than in the past, although waste-disposal innovations have been slow to emerge.

Waste management today can be divided into two major areas of emphasis: (1) the reduction of waste production at its source and (2) the development of better technologies for treating waste. It all begins with knowing as much as possible about the composition of waste.

hazardous and nonhazardous wasTe

Solid and liquid wastes are of two types: hazardous and nonhazardous. Hazardous wastes consist of liquids, solids, or gases that are toxic or cor-rosive or can ignite or react in the air or with other chemicals. Biohazards are pathogenic (disease-causing) microbes, used needles and bandages, and blood and other bodily fluids, and all of these are considered an

Waste Treatment

infectious form of hazardous waste because they might transmit disease. The U.S. Environmental Protection Agency (EPA) includes a subcategory of hazardous wastes called universal wastes. These substances do not meet the definitions given here, but they can be a hazard in the environment. Items within the classification of universal wastes are the following: bat-teries, pesticides, fluorescent bulbs, mercury-containing thermometers, and other equipment with toxic metals.

The EPA is responsible for enforcing the laws controlling hazardous waste in the United States, and it groups waste by three main methods: (1) chemical composition, (2) source, or (3) industry. When classifying wastes by chemical composition, the EPA and the waste industry fur-ther categorize the substances into the following groups, each of which have their own subgroups: chlorinated organic compounds, mercury-containing chemicals, military munitions, paint-manufacturing wastes, phenols, and radioactive wastes. Many of the most hazardous waste products from the home (paints, mercury-containing thermometers, motor oil, antifreeze, solvents, and chemical pesticides) often fit into these same categories. Another aspect of waste complicates any classifi-cation system: A large number of waste substances can belong to more than one category.

The EPA also oversees the handling of nonhazardous wastes. Though these materials are not toxic, they can fill up habitats and interfere with ecosystems if they are left unattended. Nonhazardous wastes are paper, packaging, plastic, nontoxic metals, glass, yard trimmings, wood chips, and construction waste. Municipal solid waste (MSW) also contributes to the total tonnage of nonhazardous waste. MSW contains garbage from households and businesses plus yard trimmings, wood, glass, small appli-ances, clothing, and pieces of furniture. The waste management indus-try strives to monitor MSW so that it contains only materials that do not cause harm to human or animal health or have toxic effects on the environment.

The EPAs classification of wastes based on source often gives an approximate idea of its composition as shown in the following table. These categories help waste managers speculate on the wastes general composi-tion, but they do not provide enough information to define exact compo-sition. For example, a waste manager would have a fairly good idea of the chemicals in mining wastes but would not be able to predict the day-to-day components of agricultural wastes.


Types of Waste

Type or Source Description of Contents

municipal solid waste (MSW)

household, hotels/motel, and business trash and garbage: food scraps, bottles, packaging, paper, newspapers, batteries, yard trimmings, furniture, appliances, clothing, and toys

EPA-regulated hazardous waste

hazardous substances monitored by the EPA by law: substances that are ignitable, corrosive, reactive, toxic, or etiologic

radioactive waste any solid, semisolid, or liquid waste containing radioactive elements

wastes from extraction industries

wastes from mining and mineral processing: metals, minerals, acids, and solvents

industrial nonhazardous waste

excess materials from manufacturing or energy production: pulp and paper, iron and steel, glass, plastics, and concrete

household hazardous waste

household items containing EPA-regulated chemicals: paints, stains, varnishes, solvents, cleaning chemicals, and pesticides

agricultural waste animal waste from livestock, dairies, other farm animals and wastes from crop production and harvesting: manure, feed, used bedding, carcasses, and crop discards such as leaves, vines, twigs, branches, and weeds

construction/demolition waste

debris from construction, renovations, remodeling, or demolitions: wood, concrete, brick, steel and other metals, glass, drywall, plaster, and insulation

medical waste solids generated in diagnosis, treatment, or immuniza-tion of humans or animals and from clinical, research, or manufacturing settings: unused drugs, needles, syringes, bottles and tubing, bandages, wraps, bedding, medical and dental devices, and protective clothing

(continues)

Waste Treatment

Wastes that emerge each day from cities, households, and factories do not fit into exact categories bases on composition because any waste loads components vary from one load to the next. Waste typically contains a mixture of hazardous and nonhazardous substances and an assortment of chemical and biological matter. For example, a discarded electronic device contains nontoxic plastics and metals that make up the outer shell, but it also holds toxic lead, mercury, and cadmium. Similarly, a bag of medical waste likely holds infectious microbes and blood, mercury compounds, cleaning solvents, and perhaps radioactive matter in addition to less dan-gerous items. Even if a waste load has been identified as hazardous, there may be a complex mix of hazardous substances in that one load, even newer chemicals that did not exist even a few years before. In 1980, Time magazine correspondent Ed Magnuson noted, Of all mans interventions in the natural order, none is accelerating quite so alarmingly as the cre-ation of chemical compounds.

In addition to a waste loads composition, the waste treatment indus-try considers the source of each material that requires treatment. This information helps waste managers develop better ways of sorting wastes so that hazardous materials receive the correct treatment method and nonhazardous wastes follow their own path to disposal. By knowing the composition as well as the source of a waste load, waste treatment facili-ties can predict how quickly the materials will decompose. Materials that

Types of Waste (continued)

Type or Source Description of Contents

oil and gas industry waste

solids and liquids produced in exploration, drilling, and production of crude oil or natural gas

sludge solid, semisolid, or liquids from wastewater treatment

dredging waste solids and semisolids removed from the bottom of rivers and harbors

sewage household or industrial wastewaters discharged into sewers


decompose quickly are treated differently than matter that persists for years, perhaps thousands of years. For instance bacterial toxins are lethal, yet they break down readily in normal wastewater treatment. Radioiso-topes from nuclear reactors on the other hand can persist for hundreds of thousands of years.

Modern waste management includes more responsibilities than sim-ply dispatching a fleet of garbage trucks. Part of its job now is to con-sider natural resource use and sustainability, to concentrate on making the greatest use of all components of each load for the purpose of reducing the unusable portion that goes to disposal. By reusing materials in waste, society conserves many natural resources. Waste management is, for this reason, an important part of green technology. Using less of the worlds natural resources reduces total waste output. Sustainable waste manage-ment follows a three-pronged approach to not only reduce waste but to reduce its effect on the environment and to possibly get a benefit from certain wastes. These three complementary approaches are: (1) safe and efficient handling of waste; (2) programs for reducing waste generation; and (3) recycling technology.

Sustainable waste management begins by dividing waste into two groups: preconsumer and postconsumer. Pre-consumer waste consists of the leftover materials generated in the manufacture of products. In many instances, it is recycled at the manufacturing plant so that the plant pro-duces a smaller final load. But even at top efficiency certain industries produce a lot of waste. For example, oil and gas production and the min-ing industry generate more than half of the solid waste produced in the United States each year. The EPA classifies oil and gas production wastes as wastes generated during the exploration, development, and produc-tion of crude oil, natural gas, and geothermal energy. Mining, especially mountaintop mining in which equipment slices away an entire mountain peak, creates its own unique waste problem. New York Times correspon-dent John Broder explained in a 2007 article on mountaintop mining, All mining generates huge volumes of waste, known as excess spoil or over-burden, and it has to go somewhere. Industries such as pulp and paper, metal, and agriculture also produce large amounts of solid waste. The food industryfood product companies and meat productioncontributes to the total of nonhazardous pre-consumer waste.

Postconsumer waste consists of unused materials and packaging left after consumers purchase and use products. Packaging makes up a large

Waste Treatment

proportion of postconsumer waste and much of it goes into municipal recycling programs. As sustainable waste management improves in the future, companies will be expected to reduce the amount of packaging they use in order to reduce postconsumer waste.

Industry has an important responsibility in reducing total waste pro-duced because pre-consumer waste has been estimated as 25 times that of postconsumer waste. Unfortunately, community recycling programs that handle postconsumer waste have been more successful than many industry recycling initiatives that would have an impact on pre-consumer wastes. This is because industries make economic decisions on recycling; recycling has a better chance of succeeding in industry if it helps save money. Currently, the textiles and carpet industries and paper manufac-turers produce a large proportion of this countrys pre-consumer waste.

Recyclers help sustainable waste management by knowing the poten-tial value of materials found in waste loads. The main uses for recycled waste are as raw materials for new products or as a fuel for energy produc-tion. Materials most useful for recycling are rubber, plastic, aluminum and other metals, glass, paper, and wood. The amounts of these wastes

Despite efforts to increase sustainable activities in recycling and waste-to-energy recovery, a large amount of U.S. waste continues to cause strain on landfills.


stagger the imagination: The United States discards enough aluminum each year to rebuild its entire fleet of airplanes. In order to make better use of these waste materials, more people must think of waste as a valuable raw material for new products rather than another load for the landfill. Communities can start by studying many examples of small companies that make new products from waste materials. Rubbersidewalks, Inc., is a California company that converts discarded tires into pedestrian side-walks. The innovative surfaces require fewer repairs and allow easier tree and root maintenance than more costly concrete sidewalks. A 2006 EPA press release described the environmental value of this invention: Find-ing a new use for old tires is important because piles of scrap tires can become breeding grounds for disease-carrying pests such as mosquitoes. In addition, tire pile fires are difficult to extinguish and release smoke that is dangerous to both human health and the environment. The new side-walks not only use old and unwanted tires, but they can also help save urban trees. Traditional concrete sidewalks conflict with tree growth by cutting off the roots air and water supply.

wasTe sTreamsA waste stream is the waste output of a community, region, or state and the manner in which it moves to a final disposal site. Wastes come from many directions and sources: people, farms, manufacturing plants, office buildings, households, and nature. Either as solids or liquids, these mate-rials follow a variety of routes toward specific disposal sites: recycling cen-ters, landfills, incineration plants, or sewage treatment plants.

Each waste stream starts at a source. Sources of waste range from a small rodent in a meadow to a massive manufacturing plant. A single geographic region or even a small community contains numerous routes through which waste flows: rivers, streams, storm drains, sewers, Dump-sters, garbage cans, or smokestacks. Neighborhoods have their own char-acteristic waste streams that differ from the waste streams of larger towns and cities, which differ from agricultural regions or recreational areas. A single neighborhood block may contain many places where waste starts out, beginning for instance with houses, one or more office buildings, a doctor or dentists office, a hair salon, restaurants, a park, a cleaners, and a copy shop. All of these establishments produce garbage contain-ing food, paper, electronic devices, excess furniture, clothing, etc., all the

10 Waste Treatment

components that make up MSW. After items are discarded, they take dif-ferent routes to a final disposal site. Garbage trucks pick up loads and haul them away, while lawn trimmings, pesticides sprayed on fruit trees, and animal wastes may wash into storm drains. Meanwhile, spilled gasoline, oil leaks, and car emissions add to the air, land, and water waste streams. These limited examples illustrate the enormous variety of waste streams and sources that contribute to an areas daily waste total.

Waste streams are best understood by thinking of an uncomplicated example. A toilet flushes, the material moves in pipes to a wastewater treat-ment plant where biological (microbes) and chemical (particles that cause settling) activities remove hazardous components. The treated water is reused for irrigation, sent to industrial processes, or released into a nearby body of water. A more complicated waste stream consists of many more routes and wastes that contain different substances all mixed together. In

The environment receives a diversity of hazardous materials every day. A large portion of these materials flows with rain runoff or in surface waters toward large rivers, lakes, and the ocean. Toxic substances that accumulate in aquatic ecosystems cause serious harm to food webs and biodiversity.

Assessing Global Waste Management 11

a perfect world, even complicated waste streams are controlled until treat-ment facilities remove all hazards and prevent them from reaching the environment. This is not a perfect world. People sometimes interfere with efficient waste streams by demanding that a landfill near their neighbor-hood be closed or a nuclear waste site be banned in their state. Even gar-bage hauler strikes stall waste streams and cause toxic materials to build up. When waste streams are disrupted, hazardous substances never reach their intended treatment site and instead contaminate soil and water, which then damages ecosystems.

Disrupted nonhazardous waste streams can also damage the environ-ment even though they contain no hazardous materials. For example, when garbage litters beaches or parks, it poses a danger to wildlife. Discarded fishing lines tangle birds bills and bind the mouths of marine mammals, causing them to starve. Small bits of swallowed glass or foil wrappers damage digestive tracts. Tires may block a lagoons flow and affect aquatic life in the nearby wetlands. These examples represent a small sampling of the many human activities that affect waste streams every day.

ecosysTem healThThe Earths ecosystems play a vital role in recycling nutrients. Nutrient cycling refers to the transformation of elements in nature from organic form to inorganic form and back again. Carbon, nitrogen, phosphorus, sulfur, potassium, minerals, and water all have their own cycles, also called biogeochemical cycles. In a nutrient cycle, an element or a molecule leaves a body when an animal or plant dies and decomposes. This element may then enter the atmosphere, return to the earth, be consumed as a nutrient by a living thing, and then return to the earth when the living entity dies. Ecosystem food webs contribute to nutrient recycling because nutrients move through food webs by way of a variety of single-celled and multicellular organisms. In a single nutrient cycle an element may become part of various chemical forms, in many different organisms from bacteria to large mammals. In the carbon cycle, for example, carbon takes the form of a gas, an insoluble solid, and a water-soluble compound all within one cycle, detailed in the following table.

Wastes that kill microbes or animals or stunt the growth of plants upset the carbon cycle. It is easy to imagine similar damage done by wastes to the cycling of nitrogen, sulfur, and the other nutrients. When

1 Waste Treatment

hazardous substances interfere with a cycle, the food webs that contribute to the cycle also change and ecosystem imbalance may occur. Inevitably an entire community in the environment behaves differently than its nat-ural behavior.

Perhaps the most dramatic effect of waste on a biogeochemical cycle occurs when waste pollutes the nitrogen cycle. Chemist Daniel Ruther-ford discovered nitrogen gas in 1772 and noted that it could not support life in laboratory experiments. The fact that nitrogen by itself does not support life seems surprising since nitrogen is abundant in the body, and makes up 78 percent of the atmosphere. Nitrogen occurs in thou-sands of compounds and every form of life contains nitrogen-containing

Carbon Forms as It Cycles in the Environment

Phase of the Carbon Cycle Carbons Form

atmosphere carbon dioxide gas

photosynthesis in plants water-soluble sugars

plant growth and structure insoluble cellulose, lignin, and other polysaccharides

plant decay by microorganisms cellular proteins, carbohydrates, and growth factors, and release of carbon dioxide and methane

sediments polysaccharide conversion to hydrocarbons under intense pressure and long time periods; methane and natural gas

combustion of fossil fuels (human activity)

carbon dioxide gas and volatile organic compounds

animal consumption of plants cellular proteins, carbohydrates, fats, and growth factors; respiration releases carbon dioxide gas


compounds. All amino acids contain nitrogen, therefore every protein and every enzyme contain it. The nucleic acids deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) also consist of nitrogen-containing units. The element nitrogen is therefore essential as part of many differ-ent types of organic, or carbon-containing, compounds that run cellular systems.

Nitrogen gas normally moves from the atmosphere to the earth through the action of bacteria in soil or water. These bacteria capture gas-eous nitrogen in a process called nitrogen fixation and incorporate it into their amino acids. The cells then build proteins and other compounds. From there, microbial nitrogen moves upward in food chains through plants and animals. When living matter dies and decays, the nitrogen fol-lows either of two paths: (1) nitrogen compounds return to the soil with decayed matter, or (2) specialized bacteria convert nitrogen to gas in a

The Earths nitrogen cycle usually becomes imbalanced from too much nitrogen entering the cycle rather than too little. A large influx of nitrogen-containing organic matter causes microbial blooms in water and soil. In water, microbial blooms can cause the death of aquatic species. In soil, excess nitrogen interferes with normal nitrogen reactions and plant growth.

1 Waste Treatment

process called denitrification. Wastes from agriculture, industry, and cit-ies all have the potential to interfere with several specific points within each nutrient cycle.

Two different examples of interference with nutrient cycling are pro-vided by combustion engines and agricultural wastes. When combus-tion engines burn gasoline, they put nitric oxide (NO) into the air, which converts into nitrogen dioxide gas (NO2) and nitric acid (HNO3). Nitric acid is one of the components of acid rain, which damages ecosystems by lowering pH in water and slowing plant growth. Agriculture, by contrast, produces large amounts of animal wastes and fertilizers that both contain a high concentration of nitrogen compounds. When rain washes these compounds into lakes or to the coast, algae in the water enjoy the bounty of new nitrogen and burst into a period of rapid growth called a bloom. The algae quickly use up all the other nutrients in the water and begin to die. Bacteria in the water then take their turn at the dining table by feast-ing on the algal cells. The bacterial growth is so rapid that the bloom uses up all the oxygen in the water. The entire process leading to oxygen deple-tion is called eutrophication. Invertebrates and small animal life suffocate in eutrophied waters, which affects fish that depend on these species as their food source. Next, fishing-eating mammals lose their main source of nutrients and an entire animal community suffers.

Blooms of algae are an obvious sign of an ecosystem out of balance and therefore a sign of pollution, but some forms of pollution are not as easy to spot. One example is the effect of toxic metals in soil. Soil microbes, such as bacteria and fungi, play a critical part in decomposing organic matter, but metal-laced soils kill large numbers of these microbes. As a conse-quence, a biogeochemical cycle that depends on reactions in the soil may stall. Waste management therefore can have an impact on ecosystems far away and, very often, unseen.

wasTe manaGemenTWaste management probably began in the Neolithic Age 5,000 years ago when tribes dug drainage channels for carrying waste to the nearest body of water. Water-flushed toilets date back as far as 2500 to 1500 b.c.e. in present-day Pakistan. These conveniences merely removed the sewage to a nearby ditch, but at least people were willing to invent something to carry wastes out of sight. This practice of using natural waters as a dis-


posal mechanism lasted for centuries. The Romans in the sixth or seventh century b.c.e. built the Cloaca Maxima, a great canal that carried sewage from Romes environs to the sea. In about 9 c.e., the Roman historian Livy described the systems construction by the empires working classes: . . . they felt it less of a hardship to build the temples of the gods with their own hands, than they did afterwards when they were transferred to other tasks less imposing, but involving greater toilthe construction of the bench in the Circus and that of the Cloaca Maxima, a subterra-nean tunnel to receive all the sewage of the City. The magnificence of these two works could hardly be equaled by anything in the present day. The Roman Empire of 50 to 500 c.e. further improved the water conveyances and sewers; pieces of these structures remain today.

During the Middle Ages in Europe, waste streams happened wher-ever a person opened a door and threw out their garbage. In 11th-century London the stench of waste forced the development of a new technology in waste treatment, the cesspit. These receptacles were built into the ground near houses and received a daily deposit of household garbage and human waste. Builders intended to make the cesspits leakproof, but sadly they did leak, leading to contaminated waters, orchards, and vegetable and herb gardens. Burying helped dispose of wastes a bit, but buried wastes leaked into underground water that supplied wells. Todays waste management struggles with almost the same set of problems, that is, waste streams are still threatened by accidents and leaks. Waste managers work to prevent the unintended pollution of clean water and soil with waste, and they also continue to find better ways for removing waste from peoples lives. The historian Jon C. Schladweiler on his History of Sanitation Web site (URL: http://www.sewerhistory.org/) described the progress of waste manage-ment for the last 150 years: In 184748, the British Parliament adopted a sanitary code that applied to all of England and Walesbut not London. The sewer commissioners heard about the attributes of the sewerage sys-tems developed by their ancestors on the Isle of Crete in Greece; those systems served as examples for the designers of the new sewers soon to come in the London area.

The main goal of waste management has not changed in the last cen-turies: It strives to manage waste streams. After waste streams have been properly managed to prevent leaks into the environment, and thus pollu-tion, new technologies have emerged for treating the waste and making it less hazardous to ecosystem health.

1 Waste Treatment

Modern waste treatment consists of physical, chemical, or biologi-cal methods. Physical treatment captures materials so that they cannot migrate and pollute uncontaminated places. Encapsulation, filtration, set-tling by gravity, adsorption, and stabilization are some examples of physi-cal treatment. Chemical waste treatment methods convert hazardous compounds to harmless compounds through chemical reactions. Often chemical treatment is done right at the site where contamination occurs and so it may be referred to as cleanup/treatment. Examples of chemical cleanup/treatments used today are chemical oxidation and thermal treat-ment. Thermal methods treat chemicals by destroying them in intense heat. Incineration and vitrification represent two types of thermal waste treatment: (1) incineration reduces waste to ash; (2) vitrification converts waste to a stable glasslike form. Biological treatments use microbes or plant life to degrade wastes or at least hold them in place so they do not move in the environment.

Each waste treatment method must offer cost advantages yet not injure the environment. For these reasons, waste management professionals must understand new technologies for choosing the best method for a particular task. Each waste management choice also contains special aspects such as waste transport, recycling, chemistry, biological restoration of land, and environmental law. All of these specialties play a role along the course of a waste stream until the wastes reach their final destination. Proper waste transport consists of the delivery of waste loads from their source to a final treatment or disposal site, and of all the different aspects of waste streams, transport has a visible impact on community confidence.

wasTe TransPorTPeople have always desired efficient and fast waste removal methods even if they had not yet mastered the technology to provide this benefit. Without a functioning waste removal system, societies confronted the hazards of infectious materials entering their communities. These hazardous materi-als came from animals, other people, and physicians treatment of the sick and dying. Transporting infectious waste away from a healthy population helped stop the spread of disease. Meanwhile, people disposed of non-hazardous and noninfectious wastes by the most convenient method at hand. Today, hazardous and nonhazardous waste transport has become more sophisticated and efficient. Yet the basic concept remains the same


as it was centuries ago: Remove the materials as quickly as possible from people to lessen potential health hazards.

Nonhazardous waste transport is done by companies serving a sin-gle town or a certain region. The customer (the town or region) sets up a contract with a local waste hauling company to manage its solid waste stream, its MSW. Across the United States, waste haulers daily devote almost 500,000 vehicles to pick up and transport MSW. Thirty years ago

The best methods in MSW management take advantage of new technologies in waste type separation, recycling, reclamation, and disposal. Sustainable MSW management strives to find innovative ways of rerouting as much waste material as possible for new uses and to minimize the total amount to be landfilled or incinerated.

1 Waste Treatment

these waste haulers threw nearly any type of household, office, or restau-rant waste into their trucks. Today waste hauling companies work with communities to manage their waste streams. This process usually begins by separating reusable (recyclable) from nonreusable items and keeping hazardous substances apart from the general MSW.

Waste haulers take each daily load to a centralized site called a treat-ment, storage, and disposal facility (TSDF). TSDFs are licensed facilities that are responsible for managing a communitys solid waste streams. TSDFs recover reusable items that have not already been sent to recycling. They also remove any hazardous materials that accidentally became part of the waste stream. Depending on the town and its separation/recycling needs, a TSDF may take in the additional following items: used packaging, bottles, newspapers, furniture, clothing, appliances, and yard trimmings, along with household trash and restaurant garbage, much of it food scraps. Some towns separate out many of these items before the waste hauler picks them up, but in other towns, the TSDF must separate the components of MSW. The main components in todays MSW handled by TSDFs are listed in the following table.

The EPAs Estimate of MSW before Recycling (Percentage of the 250 Million Tons

[227 million metric tons] Produced per Year)

Waste Component Percent

paper and paperboard 34

yard trimmings 13

plastics 12

food scraps 12

metals 8

rubber, leather, textiles 7

wood 6

glass 5

other 3


In most communities, construction debris, nonhazardous industrial wastes, and wastewaters are handled and transported separately from MSW. Nonhazardous materials usually go to landfills, and wastewaters flow to specialized treatment plants, which are described in chapter 7. Once the TSDF has removed recyclables and hazards, it consolidates the rest of the waste into larger loads to go to an incinerator or a landfill.

The EPA has instituted a new program called WasteWise in which the agency works in cooperation with the waste management industry to streamline waste transport. Within WasteWise guidelines, haulers focus not on the total MSW they transport but on methods for reducing the amount they transport. The EPAs WasteWise Web site states the ultimate benefit of this approach: Waste reduction makes good business sense because it can save your organization money through reduced purchas-ing and waste disposal costs. Local governments, schools, and businesses also follow the tips published by WasteWise to lower the costs they pay to waste haulers. Will waste haulers accept a program designed to reduce their profits? The EPA provides online resources that explain better meth-ods for sorting and recycling, while ensuring waste management com-panies profits do not decrease. Eventually waste managements primary focus will change from the tons of MSW transported each week to the innovations that reduce waste.

Even with a new viewpoint in waste transport, change comes slowly. Community waste management companies have adapted well to the ideas put forth in the WasteWise program, but industry lags behind. Industrial waste management remains chiefly an issue of transport and not reduc-tion. These industrial waste loads amount to hundreds of tons that move mostly by truck on common thoroughfares shared with other drivers. Railroads handle no more than 20 percent of the load and a small amount also moves by ship. Due to the enormous tonnage of industrial wastes crisscrossing the nation each day, transport remains one of the waste industrys biggest challenges.

When industrialization expanded in the 1930s and grew until the early 1980s, waste haulers had little incentive for thinking of efficiency. They carried away any and all material for a fee, whether the substances were hazardous or not. Profits accrued based on the total volume they transported or the number of pickups they made, and speed rather than careful handling equaled profits. Road accidents, spills, and improper dis-posal, plus unlawful dumping, became more and more frequent. Congress

20 Waste Treatment

responded to the growing problem of improper hazardous waste transport with the Resource Conservation and Recovery Act (RCRA). The act estab-lished a new philosophy for hazardous waste: cautious handling, trans-port, and disposal with consideration to the environment at every step along the way. To do this the RCRA mandated that all hazardous waste be tracked from point of origin to its final disposal site.

The RCRAs purpose was to increase the safety of carrying hazardous wastes through neighborhoods. According to the new law, only licensed haulers could transport the large hazardous waste loads produced by industries. Unfortunately, hazardous waste transport soon became more, not less, dangerous. Instead of paying a licensed waste hauler to comply with the regulations, companies began illegal dumping. In a 1980 Time magazine article, the correspondent Ed Magnuson wrote, One day a field in Illinois was empty; a week or so later, it contained 20,000 bar-rels of dumped wastes. Magnuson described but one of hundreds of such instances. Companies used their own trucks to unload wastes in rural areas during the night. Large tanker trucks were fitted with valves for secretly releasing liquids onto the road as they traveled. Sometimes driv-ers simply took waste-filled trucks outside of town and abandoned them. As noxious chemicals accumulated in the environment, Congress added amendments to the RCRA to further control hazardous waste transport. Today, the EPA and the U.S. Department of Transportation (DOT) share responsibility for overseeing hazardous waste transport, and the RCRA gives them the authority to enforce and fine lawbreakers.

The DOT classifies tank trucks and rail tank cars based on the type of waste they carry: combustible and flammable liquids with low vapor pressure (fuel, gasoline), flammable liquids with high vapor pressure (tolu-ene), corrosives (acids), liquefied compressed gases (chlorine, propane), or refrigerated compressed gases (oxygen). A USDOT number must appear on the tank, indicating the type of waste inside. For example DOT-412 describes a corrosive material such as hydrochloric acid. The tanks them-selves are designed to withstand corrosion from within and to prevent waste materials from igniting, exploding, or reacting with air or moisture. Tanks are usually made of steel or aluminum alloy, and newer designs might include stainless steel, titanium, or nickel. The type of tank, indi-cated by a motor carrier (MC) number, is displayed on the vehicle, and it must correspond to the USDOT number. This assures that the correct vehicle carries the hazardous waste it is designed to carry.


In the United States, the National Hazardous Materials Route Registry (the Registry) designates roads that hazardous material (hazmat) carriers may use for transporting waste. Some hazmats use only roads consist-ing of certain construction specifications and level of maintenance. The Registry periodically inspects these roads and updates the list. It drops poorly maintained roads from the list and adds new and safer roads. Some of the criteria the Registry uses in evaluating roadways are: highway con-struction, population density nearby, terrain, availability of emergency response teams, local weather, local environmental factors (earthquakes, flooding, high winds), and accident statistics.

Radioactive waste receives special attention from the DOT whether it is moved by truck, rail, or ship. Government agencies are responsible for the details of each shipment of radioactive wastes according to DOT-enforced laws. The responsibilities of the agencies are as follows:

truck transportthe Federal Motor Carrier Safety Admin-istrationrail transportthe Federal Railroad Administrationship transportthe U.S. Coast Guard

An important aspect of waste management relates to waste transport. This barge carries tons of waste down the Mississippi River. (WQPT)

Waste Treatment

The U.S. Department of Energy (DOE) designates radioactive waste shipped across the nation in the following three categories: high-level, low-level, or transuranic. High-level wastes contain the most radioactive mate-rials produced by the nuclear industry; low-level wastes consist of lower activity materials in large loads of nonradioactive matter; and transuranic wastes consist of the by-products of nuclear substance manufacture. Once the wastes have been put into these categories, each transporter follows DOT rules pertaining to the type of material to be carried. In addition to federal laws, large shipments (several tons) of high-level materials must follow state and local regulations. These regulations apply to all the areas through which a shipment travels.

Even with added regulations on radioactive waste transport, com-munities near roads and railroads that receive these transports have been concerned about potential accidents. In 2003, a team of environmental organizations filed a lawsuit to halt radioactive shipments in California and Ohio, and Charles Weems of Washington Physicians for Social Responsi-bility said in an issue of Waste News, Public health, especially the health of children, is placed at risk by trucking radioactive waste shipments that expose people to unnecessary radiation. The DOE has forecasted that 10 to 15 shipments of high-level waste per year will travel across U.S. state lines for the next several years. Furthermore, the DOE predicts that these shipments will increase to about 300 annually by 2010 and up to 1,700 by 2015. The agency has tried to assure the public that the process will be safe. The DOE has stated, The department must ship waste according to strict federal regulations. The waste will be transported in heavily shielded casks certified by the Nuclear Regulatory Commission (NRC) along approved transportation routes. Transuranic waste, which has lower radioactivity than high-level wastes, will also require thousands of shipments per year through 2015. Trucks and railroads will probably remain the main modes of transport for all of these shipments.

landfillinGDumping nonradioactive waste in remote areas outside of populated areas has been the cheapest and easiest answer to disposal for thousands of years. Garbage dumps have been discovered near many of the oldest sites studied by archaeologists; items found there have helped them learn details of early tools and implements. Landfilling does not treat waste,


however, it simply serves as a long-term storage for it. Disposal in landfills has recently begun to decrease each year because on-site cleanup/treat-ment has improved. Despite this decrease, these sites still serve as conve-nient disposal for certain nonreusable, nonrecyclable items and avoids the potential hazards of transport.

When people awakened in the 1970s to the decline of the environ-ment, concerned scientists took a close look at landfills. They found sites filled with unidentified mixtures of hazardous materials and chemicals leaching into nearby soils and groundwaters. Additional wastes washed from stockpiles with each rainfall and made their way to waterways and estuaries. A 1976 New York Times article reported on one of many exam-ples when it noted, The state has ordered New Jerseys only chemical landfill to close within ten days on charges of continued violations of environmental standards. New environmental laws began to address the hazard of poorly managed landfills. Today landfills belong to clas-sifications according to the type of waste they accept, as shown in the following table.

Landfills have been a main waste disposal method for centuries. Landfills are now reaching full capacity in many places, so waste managers now use landfills to complement waste treatment rather than serve as a sole solution for waste disposal. (Envirowise)

Waste Treatment

MSW landfills are the most common type in the United States, accept-ing about 55 percent of all MSW. (About 30 percent of MSW is recycled or composted and 15 percent is incinerated. Compost is a mixture of organic matter allowed to decompose over time.) Because so many landfills were built in the United States prior to the 1980sthere were 8,000 by the end of the decademany municipalities have little land left for additional sites, and they build fewer landfills today. Many of the existing landfills have been covered over and closed according to regulations set by the RCRA. Despite the closures, more than 2,000 landfills remain in operation, and these sites receive more careful oversight than landfills received in the 1970s80s. Landfill operators now employ new techniques in landscap-ing the waste site and also use improved containment methods to prevent materials from leaching into adjacent land and water.

Modern landfills designed for MSW are called sanitary landfills because of their leak prevention systems that keep the surroundings clean. Most sanitary landfills contain a multilayered underlining of compacted soil and leak-proof sheets of plastic. In the past, linings consisted of dense clay one-foot (0.3 m) thick plus plastic sheets, but the clay often cracked and chemicals escaped. Modern sanitary landfills use synthetic liners

Types of Landfills in the United States

Landfill Type Materials Accepted

cleanfill clean excavated soil and inert (nonreactive) materials (wood, metal, glass, paper, etc.)

industrial waste nonhazardous wastes from local industries

industrial-municipal mixed industrial nonhazardous wastes and MSW

municipal solid waste (sanitary landfills)

MSW and other inert materials

hazardous waste substances designated by the EPA as hazardous


made of high-density polyethylene (HDPE) plastic with a thickness of at least 1.2 inches (3 cm). Larger sheets minimize the number of places where sheets must be joined together and special welding provides leak-proof

Contemporary sanitary landfills use materials that hold in hazardous leachates and gases, but also help regulate gas buildup and temperatures inside the compacted waste. New landfills also incorporate sensitive monitoring systems to detect leaks, and some landfills have equipment to capture methane gas for use as an energy source.

Waste Treatment

connections between the joints. HDPE is also stronger than the plastics used in the past, but some chemicals degrade HDPE, so it does not pro-vide fail-safe protection. Even the best constructed landfills require close monitoring to assure that their contents stay in place.

Advanced landfills depend on composite systems that consist of containment layers interspersed with monitoring devices. Composite systems also contain drainpipes placed between liners to draw leachates from the load. The pumped leachates then receive treatment to remove any hazardous chemicals. Landfill operators monitor sensors to detect leachates entering the soil or groundwaters and check for excess, ignitable methane gas produced by microbes. The best sanitary landfills include a cap on top of the waste load to prevent rain from entering the load and so protect against runoff or high winds. Innovative cap arrangements consist of soil layers alternating with synthetic filters designed to control the release of gases.

Containment liners for hazardous wastes include sand and gravel lay-ers alternated with plastic netlike liners called geonets. Flexible geomem-branes, made of the plastics polyvinyl chloride or HDPE, or fabrics may also be part of the structure. Geotextiles (specialized fabrics) also help by trapping small particles to prevent clogging while allowing water to filter through. All of these innovations resist breakdown by chemicals and damage from repeated freezing and heat.

Ordinary household and restaurant garbage decomposes within land-fills in stages. First, aerobic (oxygen-requiring) bacteria and fungi digest degradable matter. In the process, they consume oxygen and produce carbon dioxide, water, and other by-products of their metabolism. The decomposition process also produces heat (122158F [5070C] inside the waste load. After about two weeks, the second stage begins in which the oxygen is gone and anaerobic bacteria predominate. These microbes cannot live in the presence of oxygen and their unique metabolism pro-duces more carbon dioxide, methane, and organic end products. Carbon dioxide and methane make up more than 90 percent of the gaseous com-pounds released from landfills, and they contribute to the atmospheres greenhouse gases. Anaerobic end products also emit unpleasant, though harmless, odors that tend to annoy communities living near even the best-managed landfills.

Landfill methane can serve as an important energy source in a pro-cess called waste-to-energy (WTE). About 425 WTE landfills operate in


43 states with at least as many additional ones planned for the near future. Energy produced this way from landfills averages 0.8 megawatts for each ton of MSW, and since 2003 landfill methane has been traded on the Chi-cago Climate Exchange and the European Climate Exchange. The Chicago Exchange allows North American corporations or towns that reduce their emissions below a set limit to sell emission credits to other organizations, or save them for the future. Meanwhile, companies having a difficult time meeting emission limits purchase credits through the exchange. Dave Miller of the Iowa Farm Bureau Federation discussed methane credits in a 2006 Brownfield News article, saying, With natural gas prices where they are, the energy system will pay for itself.

Many landfills now ban specific wastes as an extra safety measure against dangerous leachates or potential reactions within the waste load.

Biochemical reactions inside landfills emit greenhouse gases, but new technologies now capture one of these gases, methane, and reroute it as an energy source for a variety of industries.

Waste Treatment

The following banned items must follow a different waste stream to final disposal: electronics, mercury-containing items, batteries, fluorescent bulbs, and partially filled aerosol cans. Electronics may contain heavy metals or toxic flame retardants. For instance, mercury works in electrical switches, thermometers, barometers, and some medical devices. Aerosol cans contain hydrocarbon propellants such as the greenhouse gas carbon dioxide, propane, or butane, and these cans often contain paints and sol-vents dangerous to the environment. In summary, landfill management requires some knowledge of chemistry and the components that make up the enormous diversity of waste items. The following sidebar, Case Study: The Birth of a Throwaway Society, discusses the reasons why waste seems to build faster than people can treat it.

seParaTion and TreaTmenT TechnoloGy

Recovery of reusable materials relies on TSDFs to separate reusable waste from nonreusable materials. TSDFs divide materials based on chemical

T he United States produces enough wastepaper each year to build an 11-foot (3.3 m) wall coast to coast. People throw away 2 billion pieces of junk mail each year. Electronics that are barely a year old end up in landfills. Convenience foods generate tons of packaging. These are hallmarks of consumerism in Western culture. So much consumption-to-waste takes place in Western, industrialized economies that the term affluenza has been proposed to describe this unsustainable addiction to consumption, usually overconsumption. The United States and Canada may suffer more than any other nations from this affliction; the United States has less than 5 percent of the worlds population yet produces one-third of its solid waste. Over-consumption is devouring resources and producing a growing mountain of waste.

Sociologists propose several reasons why consumer product waste has grown tenfold in the last 100 years. First, wealth allows people to feel less inclined to reign in consumption to save money. Second, busy schedules lead to the use of convenience products, which generate large amounts of waste. Americans discard 130 million cell phones and 50 million computers each year. Third, innovations, especially in electronic products, make existing products become

obsolete faster than ever before. The London Times reporter Richard Morrison wrote in 2007, Does anybody [today] buy a car, a washing machine, even a toaster, in the expectation that it will last a decade? As for computers, mobile phones, iPods and all the other electronic para-phernalia of our gizmo-fixated age, well, the philosophy among manufacturers seems to be that since [people] will surely want to upgrade every twelve months, theres no reason, let alone obligation, to make products that last any longer. Finally, new electronics, furnishings, and fash-ions may meet an emotional need in a consumer-based society, which only contributes to how quickly things go obsolete.

Reversing this trend will be difficult. Success will come from a combination of personal choices in purchasing and innovations from industry that either reduce waste or make waste more recycla-ble. Community recycling programs have made strides in reducing paper, glass, and metal wastes. Industries that make fabrics, clothing, furniture, and construction materials must offer products designed for similar sustainability. Unfortunately, making conservation a priority over convenience and low cost may prove to be a difficult step for individuals and businesses alike.

Case Study: The Birth of a Throwaway Society


composition and potential health hazards and then further group mate-rials by treatment method or reuse potential. These facilities often also have the capability to chemically neutralize some hazardous substances. Overall, TSDFs play a critical role in separating solids from liquids, oils from aqueous fluids, incompatible materials from each other, and mate-rials requiring special treatment. Industrial wastes represent a complex collection of materials that TSDFs must understand in order to send them to the correct type of treatment facility. The main categories of industrial wastes managed by TSDFs are shown in the table on page 30.

Local TSDFs provide each community with information on waste sorting, what constitutes a hazardous waste, and where waste should be taken for disposal. TSDFs often provide information on how to sort car-peting, boxes, clothing, furniture, appliances, window glass, and other materials before pickup. At the facility, TSDF workers conduct additional sorting and transfer wastes into secure containers. Hazardous liquids fill 55-gallon (208 l) drums or larger mobile tanks made of steel, plastic, or fiberglass. Some TSDFs maintain open storage piles, lined and monitored similar to landfills. Once hazards have been stored in a safe container, the

T he United States produces enough wastepaper each year to build an 11-foot (3.3 m) wall coast to coast. People throw away 2 billion pieces of junk mail each year. Electronics that are barely a year old end up in landfills. Convenience foods generate tons of packaging. These are hallmarks of consumerism in Western culture. So much consumption-to-waste takes place in Western, industrialized economies that the term affluenza has been proposed to describe this unsustainable addiction to consumption, usually overconsumption. The United States and Canada may suffer more than any other nations from this affliction; the United States has less than 5 percent of the worlds population yet produces one-third of its solid waste. Over-consumption is devouring resources and producing a growing mountain of waste.

Sociologists propose several reasons why consumer product waste has grown tenfold in the last 100 years. First, wealth allows people to feel less inclined to reign in consumption to save money. Second, busy schedules lead to the use of convenience products, which generate large amounts of waste. Americans discard 130 million cell phones and 50 million computers each year. Third, innovations, especially in electronic products, make existing products become

obsolete faster than ever before. The London Times reporter Richard Morrison wrote in 2007, Does anybody [today] buy a car, a washing machine, even a toaster, in the expectation that it will last a decade? As for computers, mobile phones, iPods and all the other electronic para-phernalia of our gizmo-fixated age, well, the philosophy among manufacturers seems to be that since [people] will surely want to upgrade every twelve months, theres no reason, let alone obligation, to make products that last any longer. Finally, new electronics, furnishings, and fash-ions may meet an emotional need in a consumer-based society, which only contributes to how quickly things go obsolete.

Reversing this trend will be difficult. Success will come from a combination of personal choices in purchasing and innovations from industry that either reduce waste or make waste more recycla-ble. Community recycling programs have made strides in reducing paper, glass, and metal wastes. Industries that make fabrics, clothing, furniture, and construction materials must offer products designed for similar sustainability. Unfortunately, making conservation a priority over convenience and low cost may prove to be a difficult step for individuals and businesses alike.

Case Study: The Birth of a Throwaway Society

30 Waste Treatment

TSDF arranges transport of each type of waste to an appropriate recycling, disposal, or treatment site. In these ways, each TSDF serves as a central point in waste stream management.

Industrial wastes require more work in sorting and separating than MSW, but some communities have begun to master the difficult task of managing and recycling materials left over from industrial processes. The following sidebar, Case Study: DenmarkA Model in Waste Manage-ment, describes innovations in sustainable uses of industrial wastes.

The Salvage InduSTryThe salvage industry recovers solid wastes from manufacturing firms and sells the wastes as raw materials to other businesses. Salvaging may be considered the first true recycling operation before the terms reuse and recycling became popular.

Scrap timber and metals have been recovered for reuse since 2000 b.c.e. Prior to the Industrial Revolution, every society depended on a

Types of Industrial Wastes

Industry Types of Waste It Produces

medical medical nonhazardous, radioactive, infectious

services paper, electronics, food, furniture, clothing, packaging

education paper, electronics, furniture, chemicals

utilities cooling waters, metals, disinfectants, electronics

manufacturing packaging, raw materials, process water, leftover products

construction wood and other building materials, wire, insulation, paints

transportation fuel, tires, vehicles, food, seating, furniture, electronics

extraction mine and mill tailings, acids, equipment, metals


Denmarks coastal city of Kalundborg has developed one of the worlds premier waste management and energy-sharing plans. The plan took root after a severe water shortage in the 1980s90s, which stressed local industries. The term industrial symbiosis was coined in Kalundborg for a process whereby city and industry activities were blended into a resource-sharing system. Kalundborg works much like food webs in nature, explaining why it has been called an industrial ecosystem.

A coal-burning power plant serves as Kalundborgs central point. The town, its manufacturing, and nearby agriculture connect to each other through this energy-generating center. Wastes from several of the enter-prises serve as raw materials for others within the system. For example, a desulphurization operation within the oil refinery converts sulfur into ammonium thiosulfate fertilizer for local farms. Meanwhile, a cement manufacturer uses the power plants excess ash. Energy producers trans-fer excess heat to energy consumers, such as the municipality, and the entire system recycles energy at the same time it conserves raw materials. The head of the U.S. company Triad Energy Resources, Inc., Michael Daley, observed in the New York Times in 1999, If companies were smart, theyd all locate near sources of waste.

Kalundborg has reduced its water consumption by 25 percent by recir-culating water among the partner companies; annual water savings reach 71 million cubic feet (2 million m3) of groundwater and 35 million cubic feet (1 million m3) of surface water. Excess steam circulates through the system to enable each company to reduce oil use by substituting part of its energy needs with steam.

Twenty similar industrial ecosystems now operate in various parts of the world using Kalundborgs model. Kalundborgs power plant continues innovating by experimenting with biomass and wind energy in prepara-tion for its eventual conversion from coal to renewable energy sources.

Europe now leads the world in the amount of industrial wastes it sends to some form of waste-raw material exchange similar to Denmarks.

Case Study: DenmarkA Model in Waste Management

(continues)

Waste Treatment

cottage industry of those willing to comb through rubbish to find materi-als of value. In the 1500s, scrap dealers recovered iron from copper mining sites; in 1588, Queen Elizabeth I decreed the collection of discarded rags for use in papermaking. By the late 1800s, British workers sorted waste by hand and made a living recovering and selling any reusable materials they found. Salvaging grew in importance when the Industrial Revolution began in the 18th century and made mechanized manufacture a standard

At least one-third of all wastes in Europe go into these systems. The United States, by contrast, lags behind in the world of industrial ecosys-tems; only about one-tenth of industrial wastes in the United States go to Kalundborg-like exchange systems.

(continued)

Kalundborg, Denmark, has developed a symbiotic relationship among the municipality, the waste treatment plant, the water treatment facility, and a centralized power plant. Energy in the form of steam circulates through several industries as does treated water to assure that energy and water waste have been minimized. Some industrial wastes serve as raw material for other industries and all unusable waste then goes to the municipal treatment plant for final disposal.


way of doing business. Machines made products significantly faster than manual labor could and, as a result, employees no longer had time to save extra materials and put them back into the production line. Increased speed in manufacturing created an inevitable and mounting pile of indus-trial scraps. Entrepreneurs soon descended on the industrial wastes as waste sifters had a century earlier.

Automotive parts and construction wastes are todays most lucrative areas in the salvaging industry. Automotive salvaging recovers car, truck, and tractor parts for resale or for rebuilt parts. Scrap cars, scrap parts, mercury light switches, metals, glass, and other materials find their way into millions of new or rebuilt vehicles. For instance the steel industry recycles 14 million tons (12.7 million metric tons) of steel from vehicles, an amount equivalent to about 13.5 million new cars. Recycling businesses make the shiny model sitting in an auto showroom one of the worlds most recycled consumer products.

Japanese, German, and U.S. automakers in 2006 collaborated to cre-ate the End of Life Vehicle Solutions Corporation (ELVS). This collective effort further reduces the waste generated by the automotive industry through more efficient recycling plus innovations for reusing scrap met-als. One such device is a shredder that can turn an entire automobile body into small pieces in a matter of minutes. Skip Anthony, the sales manager for the American Pulverizer Company, told Recycling Today magazine in 2007, We listened to the mid-sized scrap dealers express a need to shred and developed our super heavy-duty 60-inch machines to fill this need.

At present, the ELVS has turned its attention to the recovery of mercury from switches, which the EPA requires must be removed before salvagers crush a vehicle. The ELVS 2006 Annual Report summarized its progress in switch recycling: The first step in implementing an ELVS switch col-lection program in a state consists of developing a list of scrap recycling facilities, vehicle recyclers, salvage yards, and auto shredders to participate in the program. ELVS sends collection buckets with educational, training, and program materials to those on the list. Participants remove switches from end-of-life vehicles and put them in the bucket. When the bucket is full . . . participants ship the container free of charge to the Environmen-tal Quality Company (ELVSs waste handler). The EPA provides further guidance through the National Vehicle Mercury Switch Recovery Pro-gram, which, despite the mercury recovery program, estimates that 67 million mercury switches are still in use in older model cars.

Waste Treatment

Todays salvage industry has become a sophisticated dealer in valuable materials. Scrap metal is one of its most important markets, led by aluminum, zinc, magne-sium, lead, nickel, stainless steel, and copper and brass, known as the red metals. Salvagers also recover iron from cast-iron prod-ucts, railroad tracks, and the steel inside tires. Other salvag-ers specialize in glass, paper, and plastics.

Outside the metals indus-try, salvagers target construction waste and demolition scraps for sale to builders of new houses and for remodeling. Many build-ers and architects are especially interested in items from very old houses because they supply a niche market seeking early 20th-century fashions: Old light fixtures, glass doorknobs, faucets, mantels, and ironwork are valuable commodities. In 2007, salvager Steve Drobinsky explained in This Old House television show, This week, one of the oldest mansions in San Francisco was being remodeled and they were removing marble sinks, cast-iron fire screens with stags and forests, a hand-carved walnut mantelone leaf over two feet long, all hand carved! I mean, what could you get that could be better than that?

conclusionThe amount of waste generated in the world is growing. It is greatest in Western cultures, and sociologists associate waste volume to the level of affluence in a society. Managing waste is one of the first steps in ensuring an ecosystem functions properly because metabolism is affected by the buildup of waste products.

Wastes are classified as hazardous or nonhazardous. Hazardous wastes are a concern because they have the potential to damage plant or animal health. The hazardous materials may be further classified in a number

The U.S. salvaging business has grown into a sophisticated arm of the recycling industry. Salvagers recover metals and melt them, as the molten bronze shows here, and then send the purified ingots to the metal industry. Mercury, palladium, platinum, brass, copper, and nickel provide examples of additional salvaged metals. (Art and Perception)


of ways: by chemical composition, by source, by the industrial activity that produced it, or whether it is biological or chemical in nature. Pre- consumer wastes are those produced during the manufacturing process, and postconsumer wastes consist of extra, unused products plus discarded packaging. Waste managers assess all these many types of waste to deter-mine how the materials are to be treated, transported, or disposed of.

Waste moves from its source to its final disposal site in a path known as a waste stream. Any waste stream can fall victim to accidents that cause spills into the environment. Hazardous and nonhazardous materi-als escaping their normal waste streams damage ecosystem health and can impose immediate health hazards on humans, animals, or vegeta-tion. Therefore, waste transport is a critical aspect of maintaining waste streams. In the United States, trucks carry most of the nations wastes to treatment and disposal sites, and any waste transport vehicletruck, rail, or shipmust abide by strict government safety regulations.

Landfills are an alternative to waste treatment. Cleanup/treatment methods are becoming more efficient and, as a consequence, the number of landfills is decreasing in the United States. Landfills still serve a pur-pose in accepting wastes that cannot be treated. Modern landfills con-tain advanced liners and caps, which have greatly reduced leaching and erosion.

Two different industries participate in making waste streams safer and more efficient. The first is the TSDF, which cooperates with communities and waste haulers to sort wastes. In doing this, the TSDF reduces the vol-ume that mus

Documents

Waste Treatment - Reducing Global Waste